nilfs2: fix regression of garbage collection ioctl

On 2.6.37-rc1, garbage collection ioctl of nilfs was broken due to the
commit 263d90cefc7d82a0 ("nilfs2: remove own inode hash used for GC"),
and leading to filesystem corruption.

The patch doesn't queue gc-inodes for log writer if they are reused
through the vfs inode cache.  Here, gc-inode is the inode which
buffers blocks to be relocated on GC.  That patch queues gc-inodes in
nilfs_init_gcinode() function, but this function is not called when
they don't have I_NEW flag.  Thus, some of live blocks are wrongly
overrode without being moved to new logs.

This resolves the problem by moving the gc-inode queueing to an outer
function to ensure it's done right.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

2 files changed, 12 insertions, 9 deletions

diff --git a/fs/nilfs2/gcinode.c b/fs/nilfs2/gcinode.c
index 33ad25ddd5c4..caf9a6a3fb54 100644
--- a/fs/nilfs2/gcinode.c
+++ b/fs/nilfs2/gcinode.c
@@ -176,7 +176,6 @@ int nilfs_gccache_wait_and_mark_dirty(struct buffer_head *bh)
 int nilfs_init_gcinode(struct inode *inode)
 {
         struct nilfs_inode_info *ii = NILFS_I(inode);
-        struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
 
         inode->i_mode = S_IFREG;
         mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
@@ -186,14 +185,6 @@ int nilfs_init_gcinode(struct inode *inode)
         ii->i_flags = 0;
         nilfs_bmap_init_gc(ii->i_bmap);
 
-        /*
-         * Add the inode to GC inode list. Garbage Collection
-         * is serialized and no two processes manipulate the
-         * list simultaneously.
-         */
-        igrab(inode);
-        list_add(&NILFS_I(inode)->i_dirty, &nilfs->ns_gc_inodes);
-
         return 0;
 }
 
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index e00d9457c256..b185e937a335 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -337,6 +337,7 @@ static int nilfs_ioctl_move_blocks(struct super_block *sb,
                                    struct nilfs_argv *argv, void *buf)
 {
         size_t nmembs = argv->v_nmembs;
+        struct the_nilfs *nilfs = NILFS_SB(sb)->s_nilfs;
         struct inode *inode;
         struct nilfs_vdesc *vdesc;
         struct buffer_head *bh, *n;
@@ -353,6 +354,17 @@ static int nilfs_ioctl_move_blocks(struct super_block *sb,
                         ret = PTR_ERR(inode);
                         goto failed;
                 }
+                if (list_empty(&NILFS_I(inode)->i_dirty)) {
+                        /*
+                         * Add the inode to GC inode list. Garbage Collection
+                         * is serialized and no two processes manipulate the
+                         * list simultaneously.
+                         */
+                        igrab(inode);
+                        list_add(&NILFS_I(inode)->i_dirty,
+                                 &nilfs->ns_gc_inodes);
+                }
+
                 do {
                         ret = nilfs_ioctl_move_inode_block(inode, vdesc,
                                                            &buffers);